Enable no-redeclare to eslint (#13452)

Author: horiaradu

.eslintrc.js

@@ -24,6 +24,7 @@ module.exports = {
         "no-new-wrappers": 2,
         "no-new": 2,
         "no-proto": 2,
+        "no-redeclare": 1,
         "no-script-url": 2,
         "wrap-iife": [2, "outside"],
         // http://eslint.org/docs/rules/#strict-mode

tasks/npm-install.js

@@ -54,7 +54,6 @@ module.exports = function (grunt) {
         delete packageJSON.devDependencies;
         delete packageJSON.scripts; // we don't want to run post-install scripts in dist folder
         common.writeJSON(grunt, "dist/package.json", packageJSON);
-        var packageJSON = grunt.file.readJSON("dist/package.json");
 
         var done = this.async();
         runNpmInstall("dist", function (err) {